Left Ventricular Shape Deformation and Mitral Valve Prolapse in Chronic Pulmonary Hypertension

Mitral valve prolapse (MVP) has been described in patients with right ventricular pressure or volume overload. The frequency of this phenomenon and its relationship to left ventricular shape and mitral valve annulus size, as well as its reversibility in chronic pulmonary hypertension, are poorly understood. We have observed an increased frequency of MVP in a patient population with chronic thromboembolic pulmonary hypertension that often resolves after thromboendarterectomy and reduction of pulmonary hypertension. To further evaluate the relationship between MVP and left ventricular shape in pulmonary hypertension, we studied 51 consecutive patients undergoing surgery for thromboembolic pulmonary hypertension. Echocardiographic features including interventricular septal position, as measured by an eccentricity index, left ventricular size, and several mitral valve annulus dimensions were evaluated prior to surgery and during the postoperative hospitalization period. The pulmonary artery systolic pressure was elevated for all patients prior to surgery, 87 ± 21 mmHg (mean ± SD). Twelve patients (23.5%) had MVP before surgery, which resolved in ten patients postoperatively. In addition, one patient whose pulmonary hypertension improved little, developed MVP postoperatively. Those patients with MVP had a greater pulmonary artery pressure preoperatively than those without MVP (102 ±19 vs 84 ±21 mmHg). The eccentricity index for those patients with MVP (1.68±0.2) was greater than for those with no MVP (1.53 ± 0.37). No significant differences were noted between groups with MVP and without MVP according to all mitral annulus dimensions or left ventricular chamber areas. Postoperatively, eccentricity index decreased significantly in both those with MVP and without MVP (1.29 ± 0.18 and 1.20 ± 0.15, respectively) as did pulmonary artery systolic pressure (67± 22 and 47 ± 13 mmHg, respectively). Mitral valve prolapse in chronic pulmonary hypertension occurs frequently and is noted particularly in those patients with the most severe pulmonary hypertension. It appears that deformation of the left ventricle is associated with echocardiographic MVP and that reduction of pulmonary hypertension reverses this deformation and allows for resolution of MVP.     

Three-Dimensional Echocardiography: Advancements in Qualitative and Quantitative Analyses of Mitral Valve Morphology in Mitral Valve Prolapse

Degenerative mitral valve disease (MVD) is the leading cause of organic mitral regurgitation (MR), one of the most common valvular heart disease in western countries. Substantial progresses in the surgical treatment of degenerative MVD have improved life expectancy of patients with significant MR. However, prognosis, surgical decision and timing of surgery strongly depend on the accurate characterization of mitral valve (MV) anatomy and pathology and on the precise quantification of MR. Three-dimensional (3D) echocardiography, a major technological breakthrough in the field of cardiovascular imaging, provides several advantages over two-dimensional (2D) imaging in the qualitative and quantitative evaluations of MV apparatus. In this review, we focus on the contribution of this new modality to the diagnosis of degenerative MVD, the quantitative assessment of MR severity, the selection and monitoring of surgical and percutaneous procedures, the evaluation of procedural outcomes. The results of a systematic and exhaustive search of the existing literature, restricted to real-time 3D echocardiography in adults, are here reported.     

High Occurrence of Mitral Valve Prolapse in Cardiac Catheterization Patients with Pure Isolated Mitral Regurgitation

ABSTRACT. Danielsen R, Nordrehaug JE, Vik-Mo H (Department of Clinical Physiology, Haukeland Hospital, University of Bergen, Bergen, Norway). High occurrence of mitral valve prolapse in cardiac catheterization patients with pure isolated mitral regurgitation. Acta Med Scand 1987; 221:33–8. The aetiological spectrum of angiographically verified pure isolated mitral regurgitation (MR) was studied in 48 consecutive adult patients (35 males). Severe MR was found in 35 patients (73%) and moderate MR in 13 patients (27%). Mitral valve prolapse (MVP) syndrome was found in 21 patients (44%). These were younger than the rest of the study population (55±13 vs. 62±6 years, p<0.05) and 15 (71%) of them were men. Endocarditis and chordal rupture occurred in 19% and 43% of the MVP patients. Sixteen patients (33%) had MR secondary to myocardial infarction while only three patients (6%) had MR of rheumatic aetiology. Bacterial endocarditis, hypertensive heart disease, hypertrophic obstructive car-diomyopathy and mitral annulus calcification were less frequently found. Mitral valve replacement was done in 20 (57%) of the patients with severe MR and MVP was the underlying disease in 15 (75%) of these patients. In conclusion, MVP is a frequent cause of pure isolated MR and of mitral valve replacement. In contrast to the preponderance of young females amongst MVP patients in population surveys, most of the MVP patients with MR in this study are middle-aged and elderly men.     

Mitral Valve Prolapse in Marfan Syndrome: An Old Topic Revisited

Background: The echocardiographic features of mitral valve prolapse (MVP) in Marfan syndrome have been well described, and the incidence of MVP in Marfan syndrome is reported to be 40–80%. However, most of the original research was performed in the late 1980s and early 1990s, when the diagnostic criteria for MVP were less specific. Our goal was to investigate the characteristics of MVP associated with Marfan syndrome using currently accepted diagnostic criteria for MVP. Methods: Between January 1990 and March 2004, 90 patients with definitive diagnosis of Marfan syndrome (based on standardized criteria with or without genetic testing) were referred to Massachusetts General Hospital for transthoracic echocardiography. Patients' gender, age, weight, height, and body surface area at initial examination were recorded. Mitral valve thickness and motion, the degree of mitral regurgitation and aortic regurgitation, and aortic dimensions were quantified blinded to patients' clinical information. Results: There were 25 patients (28%) with MVP, among whom 80% had symmetrical bileaflet MVP. Patients with MVP had thicker mitral leaflets (5.0 ± 1.0 mm vs. 1.8 ± 0.5 mm, P < 0.001), more mitral regurgitation (using a scale of 1–4, 2.2 ± 1.0 vs. 0.90 ± 0.60, P < 0.0001), larger LVEDD, and larger dimensions of sinus of Valsalva, sinotubular junction, aortic arch, and descending aorta indexed to square root body surface area, when compared with those without MVP. When echocardiographic features of patients younger than 18 years of age and those of patients older than 18 were compared, adult Marfan patients had larger LA dimension (indexed to square root body surface area), larger sinotubular junction (indexed to square root body surface area), and more mitral regurgitation and aortic regurgitation. Conclusions: The prevalence of MVP in Marfan syndrome is lower than previously reported. The large majority of patients with MVP have bileaflet involvement, and those with MVP have significantly larger aortic root diameters, suggesting a diffuse disease process.     

Dynamic Left Ventricular Outflow Tract Obstruction During Myocardial Ischemia in Mitral Valve Prolapse Syndrome

Systolic anterior motion of the mitral valve (MV) with dynamic left ventricular (LV) outflow tract obstruction is a well known phenomenon in hypertrophic cardiomyopathy, or other forms of hyper-dynamic LV function associated with hypovolemic states, or LV hypertrophy. We report three patients with MV prolapse in the absence of the above predisposing factors, who developed an LV outflow dynamic gradient during acute transient myocardial ischemia. An interaction between structural abnormalities of the mitral apparatus and ischemia-dependent LV shape deformity most likely accounted for the outflow gradient.     

The Prevalence of Mitral Valve Prolapse in Healthy Men and Women in Sweden: An Echocardiographic Study

ABSTRACT An asymptomatic population of 100 women and 101 men was studied with M-mode echocardiogram to determine the prevalence of mitral valve prolapse (MVP). One of the two patterns characteristic for MVP was found in 8% of the females and 7% of the males. The diastolic mitral valve excursion was significantly higher in the MVP group (p≤0.001). A typical M-mode pattern in combination with a high mitral valve excursion probably enhances the diagnostic specificity.     

Recovery of Heart Rate Variability and Ventricular Repolarization Indices Following Exercise

Background: There is a heightened risk of sudden cardiac death related to exercise and the postexercise recovery period, but the precise mechanism is unknown. We have demonstrated that sympathoexcitation persists for ≥45 minutes after exercise in normals and subjects with coronary artery disease (CAD). The purpose of this study is to determine whether this persistent sympathoexcitation is associated with persistent heart rate variability (HRV) and ventricular repolarization changes in the postexercise recovery period. Methods and Results: Twenty control subjects (age 50.7 ± 1.4 years), 68 subjects (age 58.2 ± 1.5 years) with CAD and preserved left ventricular ejection fraction (LVEF), and 18 subjects (age 57.6 ± 2.4 years) with CAD and depressed LVEF underwent a 16‐minute submaximal bicycle exercise protocol with continuous ECG monitoring. QT and RR intervals were measured in recovery to calculate the time dependent corrected QT intervals (QTc), the QT–RR relationship, and HRV. QTc was dependent on the choice of rate correction formula. There were no differences in QT–RR slopes among the three groups in early recovery. HRV recovered quickly in controls, more slowly in those with CAD‐preserved LVEF, and to a lesser extent in those with CAD‐depressed LVEF. Conclusion: Despite persistent sympathoexcitation for the 45‐minute recovery period, ventricular repolarization changes do not persist for that long and HRV changes differ by group. Additional understanding of the dynamic changes in cardiac parameters after exercise is needed to explore the mechanism of increased sudden cardiac death risk at this time.     

Modulation of Ventricular Repolarization and R‐R Interval Is Altered in Patients with Globally Impaired Cardiac 123I‐MIBG Uptake

Background: Cardiac ¹²³l‐metaiodobenzylguanidine (MIBG) imaging is widely used to assess cardiac sympathetic neuronal function. However, physiologic significance of impaired cardiac MIBG uptake is not fully elucidated. The purpose of the present study was to determine influences of abnormal cardiac sympathetic neuronal function on heart rate variability (HRV) and ventricular repolarization process. Methods: Twenty‐nine patients with prior myocardial infarction were divided into two groups by a heart‐to‐mediastinum ratio (H/M) of MIBG scintigraphy. Ten patients with globally decreased MIBG uptake (group I: H/M < 1.5), 19 patients with partially decreased MIBG uptake (group II: H/M < 1.5), and 17 control subjects with normal MIBG uptake (group III) were studied. Holler recording and a standard 12‐lead electrocardiography were used for evaluation of HRV, QT‐RR relation, and QT dispersion. Results. Low, high, and total frequency components decreased in groups I and II, as compared to that of group III. The reduction of these frequency domain measures was more severe in group I than in group II, but the differences did not reach statistical significance. Circadian variation of frequency domain measures disappeared in group I. The slope of QT‐RR relation was significantly greater in group I than in groups II and III. QT dispersion was also greater in group I (64 ± 25 msec) than in group 11(43 ± 19 msec) and group III (28 ± 9 msec). Conclusion. These results suggest that patients with sympathetic neuronal dysfunction inferred from globally impaired cardiac MIBG uptake have an altered modulation of ventricular repolarization process as well as decreased HRV.     

Prevalence of Mitral Valve Prolapse in Younger Patients with Cerebral Ischaemic Attacks

Abstract The association between cerebral ischaemic attacks (CIA) and mitral valve prolapse (MVP) was investigated in a blinded study of 30 consecutive patients with cerebrovascular disease and 30 control patients matched by age, sex, and immediately apparent neurological signs. All patients were below the age of 40 years. Phonocardiography, motion-mode and two-dimensional echocardiography were performed at rest and during various manoeuvres. MVP demonstrated by all three diagnostic modalities was classified as definite and prolapse in at least one but not in all three tests was designated as ambiguous. Regarding the frequency of definite MVP, no statistically significant difference was demonstrated between patients with CIA (3%) and controls (0%). Ambiguous MVP was rather common in patients with cerebrovascular disease (13%) but equally frequent in control patients (20%). It is concluded that MVP does not appear particularly common in Northern Europe in younger patients with cerebral ischaemic events.     

Tricuspid Valve Prolapse: An Uncommon Pathology Revealed by TEE

A 73-year-old male with a history of dilated cardiomyopathy and paroxysmal atrial fibrillation underwent transthoracic echocardiography (TTE) to evaluate for endocarditis due to fever and gram-positive cocci in chains on blood cultures. TTE revealed a 3 × 8 mm mass on the ventricular aspect of the tricuspid valve (Figure 1A). Subsequent transesophageal echocardiography (TEE) showed that the mass in question was actually myxomatous degeneration of the tricuspid valve (TV) and redundant chordae with significant valve prolapse. Figure 1B shows the prolapsing TV leaflets at the same level as the mitral valve. Figure 1C and ​1D1D show the valve at the level of the annulus in early systole and then prolapsing 8 mm in mid-late systole, respectively.Open in a separate windowFigure 1(A) Transthoracic echocardiography image demonstrates an apparent echo density on the tricuspid valve. (B) Transesophageal echocardiography (TEE) image demonstrates tricuspid prolapse with the mitral and tricuspid valves at equal level in systole. (C) TEE image shows the tricuspid leaflets in early systole at the level of the annulus. (D) TEE image shows the tricuspid leaflets in late systole prolapsing 8 mm into the right atrium.Tricuspid valve prolapse (TVP) is uncommon, and one study of 118,000 patients reported an incidence of 0.3%.¹ Since diagnostic parameters are not clearly defined, diagnosis is often determined subjectively. One objective criteria, > 2 mm atrial displacement of the TV leaflets in the TEE parasternal short-axis view, is noted to have high diagnostic accuracy. TVP is commonly associated with mitral valve prolapse. Patients with TVP have more severe tricuspid regurgitation and right-sided chamber enlargement compared to patients with no TVP. Due to the lack of significant tricuspid regurgitation in this case, the patient was reassured, and no further intervention was recommended.     

Kinetics of Cycle Length Dependence of Ventricular Repolarization:

Cycle Length Dependence of Repolarization. Introduction : Beat-to-beat adaptation of ventricular repolarization duration to cardiac cycle length and autonomic activity has not been previously characterized in the spontaneously beating human heart.
Methods and Results : The ECG of 14 healthy subjects was recorded from the supine and upright positions. Autonomic blockade was accomplished by atropine and propranolol. RR and RT intervals were measured by a computer algorithm, and the impulse response (h) from RR to RT computed. In the supine position the maximal adjustment of the RT interval occurred in the first beat following a change in cycle length (h_peak= 17.8 ± 1.6 msec/sec), but continued to be detectable for 3.8 seconds (2.9–4.7 sec). Propranolol attenuated the peak impulse response to 15.8 ± 4.0 msec/sec (P = NS). In the standing position the peak impulse response was increased to 25.2 ± 5.0 msec/sec (P = 0.004 vs supine), and the impulse response duration (h_dur) shortened to 1.4 seconds (1.3–1.6). This was reversed by beta blockade (h_peak= 10.7 ± 3.6 [P = 0.005 vs standing]; h_dur= 5.5 sec [4.8–6.1]). Parasympathetic and combined autonomic blockade resulted in too little residual heart rate variability to estimate the impulse response accurately. The slope of the regression of δRT and δRR in the supine position was 0.0177 ± 0.0016, which was closely correlated with the peak impulse response (r = 0.91).
Conclusions : System identification techniques can assist in characterizing the cycle dependence of veritricular repolarization and may provide new insights into conditions associated with abnormal repolarization.     

Circadian Variation of Heart Rate Variability in Postinfarction Patients With and Without Life-Threatening Ventricular Tachyarrhythmias

Circadian Variation of HRV. Introduction: Determination of heart rate variability (HRV) is widely used for noninvasive assessment of cardiac autonomic tone. A decreased HRV is associated with an increased mortality in patients surviving an acute myocardial infarction. There are, however, only sparse data about the circadian variation of different components of HRV that may be linked to the well-known circadian fluctuations in the occurrence of sudden death. In addition, the potential prognostic impact of circadian variations of HRV has not been examined. Methods and Results: The present study compared the circadian variation of HRV from 14 postinfarction patients who had survived at least one episode of out-of-hospital cardiac arrest (cardiac arrest group) with that of 14 age- and sex-matched patients without a history of malignant arrhythmias after their index infarct (control group). Several time- and frequency-domain measures of HRV were assessed from 24-hour Holter recordings. Circadian variations of high- (HF), low- (LF), and total-frequency (TF) components were determined by calculating for each parameter the hourly difference from the day's mean. The average of these differences was calculated for every hour as well as for predefined day and night periods. There was no significant difference between the two groups with regard to HRV indices that predominantly reflect vagal tone, such as SDNN (78 ± 25 vs 96 ± 24 msec), pNN50 (2.7%± 4.6% vs 4.9%± 4.2%), or HF (6.3 ± 3.0 vs 7.8 ± 3.2 msec; cardiac arrest vs control group). There was also no significant difference in the circadian variation of LF or TF between the two groups during daytime and nighttime. However, a significant difference in circadian variation of HF was found during daytime (0.02 ± 0.5 vs -0.6 ± 0.5 msec; P = 0.006) and nighttime (0.19 ± 0.64 vs 1.5 ± 0.75 msec; P = 0.0002). In cardiac arrest survivors, there was no difference in the mean deviation of HF between the day-and the nighttime periods. Conclusions: These results show an almost complete abolition in circadian variation of parasympathetic tone in postinfarction patients surviving an episode of out-of-hospital cardiac arrest, whereas circadian variation of sympathetic tone is comparable to that of postinfarction patients without arrhythmic episodes. These findings indicate that determination of diurnal variation of HRV may add to the prognostic value of HRV with respect to identifying patients at high risk of sudden death.     

经胸二维超声心动图诊断不同部位二尖瓣脱垂的准确性

目的:评价经胸二维超声心动图诊断不同部位二尖瓣脱垂的准确性及其对术式选择的指导作用。方法:本研究共入选39例患者,均经二维超声心动图诊断为二尖瓣脱垂,并对其脱垂部位,脱垂程度,反流程度及各腔室大小进行了详尽的描述。该39例患者均行外科手术治疗,并将术中所见与超声心动图结果对照,首先根据术中所见瓣叶脱垂部位将患者分为前叶病变组(n=15),后叶病变组(n=19)及双叶病变组(n=5),比较各组间临床及超声心动图特点,明确超声心动图诊断不同部位二尖瓣脱垂的准确性。同时根据手术方式将患者分为瓣膜置换者(n=23)与瓣膜成形者(n=16),比较两类患者间的超声心动图特点。结果:39例患者中,超声心动图诊断与术中所见比较二尖瓣前叶病变组,后叶病变组及双叶病变组分别为14例及15例,22例及19例、3例及5例,诊断瓣叶脱垂伴腱索断裂者为17例及22例,与术中所见比较,该四者的准确率分别为92.3%,87.1%,89.7%及72%。在选择不同手术方式的比较的结果为,二尖瓣前叶及双叶脱垂者多行瓣膜置换术,二尖瓣后叶病变者多行瓣膜成形术。结论:二维超声心动图不仅能较准确地诊断不同部位的二尖瓣脱垂,同时对手术方式的选择具有重要的指导作用。     

Factors influencing heart rate variability in patients with severe aortic valve disease

Background and hypothesis: Heart rate variability (HRV) is an accepted tool for the assessment of cardiovascular autonomic tone. There are no sufficient data concerning its application to patients with severe aortic valve disease (AVD) requiring cardiac surgery. Methods: It was the aim of this study to examine HRV and its physiologic correlates in patients with severe aortic valve disease requiring cardiac surgery. The correlates of time domain indices of HRV obtained from 24-h Holter electrocardiographic recordings were analyzed in 36 consecutive patients (23 men and 13 women, mean age 62 ± 11 years) with AVD prior to cardiac surgery (aortic stenosis: 17 patients, aortic valve regurgitation: 3 patients, combined aortic valve disease: 16 patients). Results: Low values of HRV were found in the entire study group: SDNN 96.8 ± 30.9 ms, SDNNI 39.3 ± 14.4 ms, SDANN 86 ± 28.9 ms, and RMSSD 30 ± 18.1 ms. In a univariate analysis, there was no significant correlation between the time domain measures of HRV and age, gender, medication, left ventricular ejection fraction, peak aortic pressure gradient, fraction of aortic valve regurgitation, and left ventricular mass assessed by echocardiography. Patients in advanced functional classes of heart failure [New York Heart Association (NYHA) III or IV] had significantly lower values for SDNN (83.8 ± 33.6 vs. 107.3 ± 24.7 ms; p<0.05) and SDANN (72.7 ± 29.4 vs. 96.6 ± 24.3 ms; p<0.05) than patients in NYHA class I or II. Reassessment of HRV 1 week after aortic valve replacement was performed in 17 patients and showed a significant further decrease of SDNN (102.4 ± 29.7 vs. 61.5 ± 23.5 ms; p<0.001), SDNNI (40.7 ± 13.6 vs. 23.4 ± 12.4 ms; p<0.001) and SDANN (91.8 ±29.2 vs. 54.2 ± 22.8 ms;p<0.001). Conclusion: Patients with AVD requiring cardiac surgery reveal reduced time domain indices of HRV. This observation is pronounced in patients with a progressed clinical class of heart failure, whereas hemodynamic and echocardiographic parameters seem to have no significant influence on HRV parameters in this population. In addition, there is evidence of a further reduction of HRV time domain indices 1 week after uncomplicated aortic valve replacement.     

Transesophageal Echocardiographic Findings of a Patient with Hypertrophic Cardiomyopathy, Mitral Valve Prolapse, and Coronary Artery Disease

The coexistence of hypertrophic cardiomyopathy and mitral valve prolapse has been previously described, but it is not a common finding. We describe the transesophageal echocardiographic findings of a patient with hypertrophic obstructive cardiomyopathy, mitral valve prolapse, and coronary artery disease.